Spiral winding device



G. F. HOLTQN SPIRAL WINDING DEVICE Filed Jan. 21, 1964 3 Sheets-Sheet l GEORGE F. HOLTON BY Aug. 3%, 396 s F. momom 3,269,,m2

SPIRAL WINDING DEVICE Filed Jan. 21, 1964 3 Sheets-Sheet 2 INVENTOR.

GEORGEFHQLTON ATTORNEYS 9, 1966 G. F. HOL'TQN BQWJQEZ SPIRAL WINDING DEVICE Filed Jan. 21. 1964 3 Sheets-Sheet 5 INVENTOR: 650E655 F. HOLTQN ATTORNEVfi United States Patent 3,269,102 SPIRAL WHNDWG DEVIQE George F. Holton, Kennett Square, Pa, assignor to National Vulcanized Fibre Company, a corporation of Delaware Filed Jan. 21, 1964, Ser. No. 339,187 8 Claims. (Cl. 57-13) This invention relates to winding devices, and more particularly to winding machinery and method for applying wrapping material to a cylindrical workpiece in an even spiral pattern.

The manufacture of laminated cylindrical structures, for instance forming an outer fibreglass covering 011 laminated fibre tubes for producing fuse tubes and the like, requires that the layers be evenly applied to attain a satisfactory and uniform product. It has been the practice to wrap inner tubes in large sheets of outer material, such as resin coated fibreglass, by simply rolling a sheet around a tube a number of times to build up the desired thickness of outer material. Then, the tubes are cured in ovens to obtain the desired fusing between the layers, and the tubes are thereafter finished in the desired manner depending upon the requirements of the particular product. However, the wrapping of tubes in large sheets is relatively expensive because of the high initial cost of forming the material into sheets.

Consequently, attempts have been made to provide an outer lamination by wrapping resin coated strands of material on the tube in a helical pattern. To make this process competitive, it is desirabel to apply a large quantity of wrapping material at one time; also, since the strands are wrapped under tension, strands fed from a single radial direction tend to bend or how the tube in the region of wrapping. As a result, machinery has been proposed for directing strands of wrapping material to the tube from a plurality of opposed radial paths.

However, the strands of wrapping material in the separate opposed paths are subject to fluctuations in tension, which is extremely difficult to control. Consequently, this method has previously been used successfully only where the tension on the wrapping material could be extremely low, or with relatively thick or relatively short mandrel supported tubes which were not subject to lateral flexing caused by the diverse higher tensions. Previously, when attempts were made to apply higher tensioned material to very long or very thin tubes, the unpredictable lateral flexing of the tubes induced by unequal tensions caused the wrapping material to spiral on the tubes with an inconsistent helix angle which caused overlapping of adjacently spiraled strands or gaps between adjacently spiraled strands, both of which conditions are wholly unsatisfactory for fuse tubes and like products. While it is of course economically desirable to wrap tubes which are as long as possible to minimize the percentage of end wastage where the strands of wrapping material are not applied in an even helical pattern, the wrapping of flexible tubes under more than negligible tension has heretofore been singularly unsuccessful.

Accordingly, it is an object of the present invention to provide a spiral winding device and method for applying an outer lamination on tubes which obviates the above problems.

It is another object of the present invention to provi-de a spiral winding device including means for applying wrapping material under tension to a laterally flexible cylindrical workpiece from plural circumferentially spaced points at a helix angle which is constant.

Another object of the present invention is to provide a spiral winding device including guide shoe means pivoted to ride against a cylindrical workpiece and shaped to con 3,269,102 Patented August 30, 1966 trol the travel of material in predetermined fashion relative to the workpiece itself.

Other objects of the present invention will become apparent to one skilled in the art from a reading of the following description in conjunction with the accompanying drawings, wherein similar reference characters refer to similar parts and in which:

FIG. 1 is a sectional elevational view on line 1-1 of FIG. 2 showing in semi-schematic fashion the winding device of this invention;

FIG. 2 is a plan view of the winding device of FIG. 1 with the coating tank omitted for purposes of clarity;

FIG. 3 is a plan view on an enlarged scale showing details of the winding device;

FIG. 4 is a front sectional elevational view on line 4-4 of FIG. 3 showing details of the winding device;

FIG. 5 is a fragmentary perspective sectional view on line 5-5 of FIG. 3;

FIG. 6 is a modified version of the winding device of this invention; and

FIG. 7 is another modified version of the winding device of this invention.

Referring to the drawings, as shown in the embodiment of FIGS. 1-5, the apparatus includes feed means for wrapping material and means for rotating an elongated cylindrical workpiece, while relative axial motion is generated to form a spiral winding. For instance, a tubular Workpiece it) may be snugly received for the winding step on an elongated cylindrical rod or mandrel 12 which may be chucked for axial rotation as at 14 at one or both ends thereof. A motor or other drive means 16 is connected, as at 18, to impart rotary motion to the workpiece 10 about its longitudinal axis by means of the chuck 14. This mechanism is shown in purely schematic fashion as its nature is readily understood and it forms no part of the invention per se.

Transversing axially of and parallel with the rotated workpiece 10 is a feed means 20 which comprises a main frame 22 mounted for reciprocal motion including an integral traveling nut 24 threaded on a rotating screw 26. The screw 26 is suitably journaled in known fashion parallel and generally co-extensive with the chucked workpiece 10, and is driven by a motor or other drive means 28 connected, as at 38, with the rotating lead screw. Either the motor 28 or the connecting mechanism 30 includes reversing mechanism to enable the frame 22 to be reciprocated to and fro relative to the workpiece, as can be understood. Suitable limit switches or other such known means may be provided to actuated the reversing mechanism automatically when the feed means has traversed the full length of the lead screw. Again, this traversing mechanism is not shown in full detail because its operation is readily understood and it forms no part of the invention per se.

A cantilevered support member 32 secured at 34 to the traversing frame 22 carries a depending support member 36 adjustably secured at 38 to the outer end thereof in a position above the workpiece 10. A yoke member 40 rigidly secured at 41 to the support member 36 is positioned transverse to the workpiece axis and partially encircles the workpiece in a manner which provides an intervening space between the workpiece and the yoke. A pair of smooth surface cylindrical guide rods 42 and 44 are secured at their rear ends to the yoke 40 parallel to the workpiece axis. The guide rod 42 is fastened by suitable means 46 above and to the right of the workpiece as viewed in FIG. 4. The guide rod 44 is similarly secured on a rigid yoke extension 48 below and to the left of the workpiece 10 as viewed in FIG. 4.

A pair of arms 50, 52 are freely pivoted at 54, 56, respectively, on opposite ends of the yoke 40 diametrally 35 spaced from the axis of the workpiece 10. Each arm 50, 52 carries a guide shoe 58, 60, respectively, rigidly secured at their rear portions at 62, 64 thereon.

The guide shoes 58, 60 are positioned in opposed relation to each other, and are essential duplicates of each other. Each comprises a semi-circular length of smooth metal rod attached at the rear end leaving the front end free for easy threading of strands of wrapping material thereover. The mid portion of each curved rod is flattened tangentially on its inner portion at 66, 68 to form a smooth flat surface parallel to the axis of the workpiece. Additionally, each flat surface 66, 68 includes an overhanging shoulder or lip 70, 72 having an inner fiat surface angled to the first flat surface at about 135 which also lies in a plane parallel to the workpiece axis. As shown in FIGS. 4 and 5, the fiat surfaces 66, 68 are substantially parallel to each other and, with a relatively small workpiece disposed therebetween, lie at an angle of approximately 45 to the line which extends through the two pivot points 54, 56 and the workpiece axis; the two surfaces 70, 72 are also substantially parallel to each other and to the line which extends through the pivot points 54, 56 and the workpiece axis. Consequently, it will be noted that each guide shoe 58, 60 makes line contact with the elongated workpiece along each of its two flat surfaces. Also, as a workpiece increases in diameter, it will be clear that the arms 50, 52 may swing about their pivot points 54, 56 to maintain the two lines of contact of each shoe with the workpiece while maintaining the workpiece in its desired central position.

The outer surface of each guide shoe 58, 60 is curved in semi-circular fashion to act as a guide for strands of wrapping material to insure that the strands are applied to the rotating workpiece from predetermined radial paths and at a constant helix angle. For instance, in FIG. 3, the shoes 58, 60 attached to the framework are moving in the direction of the arrow 74 relative to the workpiece 10. In this condition the strands 76, 78 of wrapping material are guided across the outer rear portion of the shoes adjacent where they are attached to the framework. When the framework traverses in the opposite direction relative to the workpiece, the strands 76, 78 of wrapping material are guided across the outer front portion of the guide shoes remote from where they are attached to the framework, as can be appreciated.

The strands of wrapping material such as fibre glass, as best seen in FIG. 1, are supplied from a series of roll means such as the roll means 80 including tensioning means 81. By means of well-known guides 82, the wrapping material is directed in grouped strands through suitable coating resin 84 in a tank 86 mounted on the framework 22 to traverse therewith. After passing through the coating mixture, the strands of wrapping material pass through mechanism 88 for regulating the quantity of coating material on the strands.

Thereafter, they follow separate predefined paths to be fed to the workpiece by the guide shoes 58, 60. For instance the strand 76 passes over the guide bar 42 and then is directed to the outer rounded surface of the guide shoe 58, and then beneath the guide shoe and up to the workpiece 10. The strand 78, on the other hand, passes under the guide bar 44 and then is directed to the outer rounded surface of the guide shoe 60, then above the guide shoe and down to the workpiece 10.

To balance the effect of the guide shoes on a workpiece, an extension 90 is provided for the arm 52 extending in the direction opposite the pivot 56. An adjustable weight 92 is positioned on the arm extension 90 and includes a set screw 94 for securing the weight in the desired position. This results in a natural gravitational influence tending to bias the guide shoe 60 upwardly with a force equal to the downward gravitational force acting on the pivoted guide shoe 58. Thus, both shoes 58, 60 are biased equally away from the workpiece in the static condition when no wrapping material is pulling them into contact with a workpiece. Consequently, when the machine is in operation and wrapping material draws the shoes 58, 60 against the workpiece, any difference in pressure on the workpiece from the shoes is not caused by the weight of the shoes themselves.

In operation, the device of FIGS. 1-5 operates in continuous fashion to apply wrapping material to a rotating workpiece in an even manner. Strands 76, 78 of wrapping material (which in practice may be considerably thicker than the ones shown in the drawings for purposes of illustration) are threaded as described above on the yoke supported guide members and given an initial wrapping around a fibre tube 10 supported on a mandrel 12 which is chucked for axial rotation as at 14. Actuation of the motor 16 and the motor 28 rotates the workpiece to gather wrapping material therearound. Because of the tensioning mechanism 81 on the wrapping material, the strands 76 and '78 pull the guide shoes 58, 60 into contact With the workpiece. The longitudinal traversing of the framework 20 by means of the lead screw 26 causes the wrapping material to be applied to the workpiece in a spiral pattern. Repeated back and forth traversing of the frame 20 increases the thickness of the wrapping material on the tubular workpiece. Rotation of the mandrel may be continued until the desired thickness of the outer lamination is built up. The speed of workpiece rotation and the rate of feed mechanism traverse are regulated according to the combined thickness or Width of the strands of wrapping material to obtain the desired tensioned, even spiral winding elfect.

As the thickness of the workpiece 10 increases, the shoes 58, 60 on the arms 50, 52 pivot outwardly slightly about their respective pivot points 54, 56 on the yoke 40. If the wrapping material in one of the strands should exert greater tension force on the workpiece than the other strand, the workpiece will not be pulled or bowed out of its central position. The presence of the lips 70, 72 on guide shoes 58, 60 serve to keep the workpiece in contact with the flat surfaces 66, 68 regardless of tension fluctuations. Additionally, the geometry of the guide members is such that the unequal tensioning in the different strands of wrapping material has as little effect as possible on the pressure with which each guide shoe rides on the workpiece. For instance, with a relatively thin workpiece between the guide shoes, the strands of wrapping material 76, 78 between their respective .guide rods 42, 44 and their guide shoes 58, 60 are in parallel paths which lie at an angle of approximately to the line which runs through the pivot points 54, 56 and the workpiece axis. While this angle will obviously increase very slightly as the diameter of the workpiece increases, the geometry of the mechanism is such that the tension forces transmitted to the guide shoes are minimized, and even those forces are counteracted by the lip surfaces 70, 72.

By providing the fiat surfaces 66, 68 on the inner faces of the guide shoes 58, which actually contact the workpiece, the wrapping material has a very short and positively predetermined free flight between the guide shoes and the workpiece. This cancels variations in the helix angle at which the material is applied and insures that the radial direction of the opposed paths is constant as determined by the lips 70, 72.

In FIGS. 6 and 7, modified embodiments of the present invention are illustrated for the purpose of illustrating several of the many possible equivalents of this invention. In FIG. 6, a trio of guide shoes 100, 102 and 104 fixed on arms 106, 108 and 110 are pivoted respectively at 112, 114 and 116 on a semi-encircling yoke 118 supported on a framework 120. The three guide shoes ride on a centrally located workpiece in the manner of the guide shoes in the FIG. 1-5 embodiment to direct wrapping material to the workpiece from three equally spaced radial paths, and at a constant helix angle. In FIG. 7, a quartet of guide shoes 200, 202, 204 and 206 secured on arm members 208, 210, 212 and 214 are pivoted respectively at El) 216, 218, 220 and 222 on a semi-encircling yoke 224 secured to a frame 226. The four guide shoes ride on a centrally located workpiece in the manner of the guide shoes in the FIG. 1-5 embodiment, to direct wrapping material to the workpiece from four equally spaced radial paths and at a constant helix angle.

Thus, a spiral winding device has been disclosed which directs wrapping material from plural equally spaced paths to a rotating workpiece at a constant helix angle to avoid gapping or overlapping in the wrapping. Additionally, such wrapping may be accomplished in the preferred higher tension ranges on the preferred long workpieces of any thickness or strength without adverse effects from lateral flexing or bowing.

While the above described embodiments represents preferred modes of carrying out the present invention, other embodiments may be restored to within the scope of the actual invention, which is claimed as follows.

What is claimed is:

1. A winding machine for applying wrapping material to an elongated workpiece in a spiral pattern comprising guide means for supplying wrapping material under tension to the workpiece and for controlling the helix angle of the wrapping material, the guide means including plural shoe members, each mounted for shifting motion to ride against the workpiece and shaped to direct the travel of wrapping material to the workpiece from plural circumferentially spaced radial paths at a constant helix angle.

2. A winding machine comprising feed means for supplying wrapping material under tension to an elongated and laterally flexible cylindrical workpiece, first drive means connected to rotate the workpiece about its longitudinal axis to gather wrapping material therearound, second drive means connected to cause relative axial motion between the feed means and the rotating workpiece to apply the wrapping material to the workpiece in a helical pattern, the feed means including guide means positioned to supply wrapping material to the workpiece from plural, equally-spaced radial path and to control the helix angle of the wrapping material as well as centering means to positively insure that the radial distance between the guide means and the workpiece is constant despite variations in tension on the wrapping material in different paths.

3. A winding machine comprising feed means for supplying wrapping material under tension to an elongated and laterally flexible cyclindrical workpiece, first drive means connected to rotate the wrokpiece about its longitudinal axis to gather wrapping material therearound, second drive means connected to cause relative axial motion between the feed means and the rotating workpiece to apply the wrapping material to the workpiece in a helical pattern, the feed means including guide means positioned to supply wrapping material to the workpiece from plural, equally-spaced radial paths as well as shiftable means to positively insure that the helix angle at which wrapping material is applied to the workpiece from the different paths is similar despite variations in tension on the wrapping material in diiferent paths.

4. A winding maclhine comprising feed means for supplying wrapping material under tension to an elongated cylindrical workpiece, first drive means connected to retate the workpiece about its longitudinal axis to gather wrapping material therearound, second drive means connected to cause relative axial motion between the feed means and the rotating workpiece to apply the wrapping material to the workpiece in a helical pattern, the feed means including at least one guide shoe, means mounting the guide shoe for shifting to and fro to ride against the workpiece, and the guide shoe being shaped to control travel of wrapping material to the workpiece in a predefined path directed to bias the workpiece and the guide shoe into contact while minimizing the tendency to bias the workpiece laterally.

5. A winding machine comprising feed means for supplying Wrapping material under tension to a cylindrical workpiece, first drive means connected to rotate the workpiece about its longitudinal axis to gather wrapping mate rial therearound, second drive means connected to cause relative axial motion between the feed means and the rotating workpiece to apply the wrapping material to the workpiece in a helical pattern, the feed means including a yoke member extending laterally of the workpiece at a distance therefrom, guide means for controlling the helix angle of the wrapping material, the guide means including plural guide shoes each including at least one surface for contacting the workpiece and a curved surface generally tangent with a line parallel with the workpiece axis for guiding wrapping material to the workpiece in either direction of relative axial motion, means mounting each guide shoe on the yoke member for shifting movement to and from the workpiece whereby the shoes may continually contact a workpiece as its dimension changes.

6. The winding machine as claimed in claim 5 including means connected to balance the guide shoes to provide substantially equal pressure of each on a workpiece.

7. The winding machine as claimed in claim 1 wherein each of the shoe members includes a first portion for riding against the workpiece and an offset lip for also riding against the workpiece, and the shoe members being symmetrically arranged about the workpiece whereby wrapping material passes around and in contact with each shoe member before being Wrapped around the workpiece to maintain the shoe members against the workpiece for minimizing the tendency to bias the workpiece laterally.

8. A guide shoe for controlling the helix angle of wrapping material in a winding machine therein the wrapping material is applied to an elongated workpiece in a spiral pattern comprising a body member for disposition adjacent the workpiece, workpiece contacting means on the body member for reacting against the workpiece to minimize any tendency of the workpiece to bias laterally as the wrapping material is applied to the workpiece, the contacting means being a first portion for riding against the workpiece and an offset lip for also riding against the workpiece, guide means on the body member for guiding the wrapping material to the workpiece, and the guide means being a curved surface shaped for being tangent with a line parallel to the workpiece axis whereby the wrapping material may pass around the curved surface before being applied to the workpiece and the wrapping material maintains the workpiece against the contacting means when the wrapping material is applied to the workpiece.

References Qited by the Examiner UNITED STATES PATENTS 544,847 8/1895 Downes 5713 X 73 6,178 8/1903 Varley 5716O 1,625,983 4/1927 Carter 57-160 X 2,619,788 12/1952 Grieve 57--13 3,136,113 6/1964 Cullen et al. 57-160 3,137,985 6/1964 Bailey 5713 FRANK I. COHEN, Primary Examiner.

MERVIN STEIN, STANLEY N. GILREATH, D. E.

WATKINS, Assistant Examiners. 

1. A WINDING MACHINE FOR APPYING WAPPING MATERIAL TO AN ELONGATED WORKPIECE IN A SPIRAL PATTERN COMPRISING GUIDE MEANS FOR SUPPLYING WRAPPING MATERIAL UNDER TENTION TO THE WORKPIECE AND FOR CONTROLLING THE HELIX ANGLE OF THE WRAPPING MATERIAL, THE GUIDE MEANS INCLUDING PLURAL SHOE MEMBERS, EACH MOUNTED FOR SHIFTING MOTION TO RIDE AGAINST THE WORKPIECE AND SHAPED TO DIRECT THE TRAVEL OF WRAPPING MATERIAL TO THE WORKPIECE FROM PLURAL CIRCUMFERENTIALLY SPACED RADIAL PATHS AT A CONSTANT HELIX ANGLE. 